1. Field
Non-limiting example embodiments of the present invention relate to the electronic valve systems for an internal combustion engine.
2. Related Art
Conventionally, internal combustion engine valve operation has been controlled using camshafts mechanically linked to the rotation of the engine crankshaft. With the continued aim of engine and vehicle manufacturers to improve engines by way of reducing emissions and fuel consumption, and to increase performance for better driveability, various techniques to improve valve control have been employed, such as, variable valve timing.
In order, further, to provide better control of valve actuation, it is proposed to employ electronic valve actuation systems. Electronic valve actuation is also sometimes known as electro-magnetic valve actuation, electro-mechanical valve actuation, electrical valve actuation and the like. For consistency, the term electronic valve actuation will be used herein. An electronic valve actuation system can be achieved by replacing an intake camshaft with electrically activated valve actuators, for example electromagnetic valve actuators, driven by a valve control unit (VCU). Using information received from an engine control unit (ECU), the VCU can drive the actuators in order to open and close the valves at given lift and transition times in response to valve timing requests from the ECU. The VCU can then inform the ECU of the applied valve timings.
Through such a system, independent open and closing of intake valves at prescribed crankshaft angle timings, transition time and lift can be based on requests from the ECU.
Non-limiting example embodiments of the present invention seek to address the safe operation of an engine with electronic valve actuation in the situation where an intake valve failure occurs.